Tribological and structural properties of lubricating films of Al–4Si–20Pb alloy during dry sliding at different temperatures

The friction and wear behaviour of an hot extruded Al–4Si–20Pb alloy was investigated under dry conditions in a temperature range 25–200 °C using a pin-on-disc type wear testing machine. The results show that the material demonstrates good friction and wear properties, the almost constant wear rate and lowest level in coefficient of friction at room temperature and 373 K is attributed to a lubricating film covering almost the entire worn surface. X-ray photoelectron spectroscopy and X-ray analyses reveal that the lubricating film is a mixture of Fe2O3, Pb4SiO6 and a small amount of Fe2O3 at room temperature, and a mixture of Pb4Al12(SiO3)7, SiO2, Al2O3 and a small amount of Fe2O3 at 373 K.